Understanding Adobe Photoshop CS4- P6

Understanding Adobe Photoshop CS4- P6

Understanding Adobe Photoshop CS4- P6: Learning Adobe Photoshop is essential to success in digital media industries.
Photoshop is a gateway into several related technologies. From digital image acquisition
and processing to typography and compositing, Photoshop is often your fi rst
introduction. If you can master this program, you can go on to success with several
other technologies. With this in mind, it is important to learn Photoshop with one
eye on the present and the other on the future.

Nội dung Text: Understanding Adobe Photoshop CS4- P6

138 Chapter 8 Compositing with Layers
TIP • If you need a ﬂattened copy to paste into another document (or
within your current document), use the Copy Merged com-
Flattening Images
mand. Select an active, visible layer, and then choose Select >
Remember, ﬂattening is permanent. All. You can copy all visible items to your clipboard as a single
Be 100 percent positive before you
layer by then choosing Edit > Copy Merged or by pressing
discard your layers permanently.
Shift+Command/Ctrl+C.
Saving a ﬂattened copy is usually
a better idea. You can also group
multiple layers into a Smart Object
by selecting the layers, and then Creating a Panorama
choosing Layer > Smart Object >
Convert to Smart Object. You can By using layers, you can take several photos from one location and
always edit the Smart Object and merge them together to create a large panoramic photo. Many
extract the layered ﬁle. people take an assortment of photos of a subject while holding the
camera, but it’s best to use a tripod. It’s important to ensure that
you have some overlap between each frame; that is to say, the adja-
cent photos share some common subject matter—about 15 percent
overlap is usually enough.
Let’s try piecing together some photos using the Automation com-
TIP
mand called Photomerge:
Professional Panoramic
Photography 1. Choose File > Automate > Photomerge. Photomerge is a
Pros know that it’s best to use a specialized “mini- application” within Photoshop that assists in
tripod and slightly move the camera combining multiple images into a single photo.
to create overlap. There are even
2. Click the Browse button and navigate to the Chapter 8 folder
specialized tripod heads that you
on the book’s CD.
can purchase from companies like
Kaidan (www.kaidan.com) and 3. Select the folder Ch08_Pano, select all the ﬁ les within the
Really Right Stuff (www.reallyright folder, and then click Open.
stuff.com) that make leveling and
rotation much more precise.

Creating a Panorama 139
4. There are several Layout options avail-
able that attempt to ﬁ x problems caused by
panoramic photography (such as distortion).
A good place to start is Auto, which attempts
to align the images but will bend them as
needed.
5. Select the check boxes next to Blend Images
Together and Vignette Removal. These two
options will attempt to blend the edges of the
photos together and can hide subtle differ-
ences in exposure.
6. Click OK to build the panoramic image.
Photoshop attempts to assemble the panora-
ma based on your choices in the dialog box.
Since layers are preserved, however, you can still tweak the
position of individual layers.
7. Nudge any layers with the Move tool if your
alignment is off.
8. The Layer Masks help to blend the photos
together. They can be modiﬁed as needed
using the techniques you learned in the
previous chapter.
9. Choose Layer > Flatten Image.
10. Crop the image to a clean rectangular shape
using the Crop tool (C).
Be sure to check out the ﬁ le Ch08_Pano_
Complete.tif to see how the image was further
enhanced with adjustment layers.

140 Chapter 8 Compositing with Layers
Auto-Aligning Layers
The technology that powers the Photomerge
command can also be harnessed to stitch
together nonpanoramic shots. The Auto-Align
Layers command is a useful way to stitch to-
gether multiple shots or scans of a large object or
a group photo. The command is very easy to use
and produces impressive results.
1. Choose File > Scripts > Load Files into
Stack to combine two or more ﬁ les into one
document.
2. In the Load Layers dialog box, click the
Browse button to navigate to the ﬁ les
you need.
3. Open the folder Ch08_Cyborg, select both
images inside, and click Open.
4. In the Load Layers dialog box select the
check box next to Attempt to Automatically
Align Source Images.
5. Click OK. Photoshop opens both images and
aligns them, and does a good job (especially
since the top layer was taken at such an
angle). This alignment can be reﬁ ned even
further.
6. Make sure both layers are selected in the
Layers panel.
7. Choose Edit > Auto Align Layers.
VIDEO
27 TRAINING
Creating Panoramas

Auto-Aligning Layers 141
8. Select the Auto option to enable both
Vignette Removal and Geometric Distortion
options for Lens Correction.
9. Click OK. Photoshop removes some of the
distortion in the glass case, giving it a more
rectangular shape.
The layers can be seamlessly blended togeth-
er using the Auto-Blend Layers command.
This applies Layer Masks as needed to each
layer to mask out exposure issues and create
a seamless composite.
10. Choose Edit > Auto-Blend Layers, specify
the Panorama method, and click OK (be sure
the Seamless Tones and Colors check box is
also selected).
11. Crop the image as needed, adjust Levels,
and Flatten.

142 Chapter 8 Compositing with Layers
LAYER COMPS
Photoshop CS introduced Layer Comps, which allows Photoshop to memo-
rize combinations of layer visibility, opacity, and position. This can be useful
for storing multiple designs inside one document. When experimenting
with layouts, you’ll often use several options in one document. You might
set the headline in three different typefaces and try the main photo in two
different positions. Using Layer Comps allows you to set up different options
within one document (instead of having to save and keep track of several).
1. Open the ﬁle Ch08_Layer_Comps.psd.
2. Make sure the Layer Comps window is visible. If not, choose VIDEO
Windows > Layer Comps. 28 TRAINING
Layer Comps
3. Click the forward triangle to Apply Next Selected Layer Comp.
Click through and examine the different layer comps.
4. For Layer Comp 1, move the words around onscreen to a new position.
5. Click the Update layer comp icon at the bottom of the Layer Comps panel (it looks like two arrows in a circle),
6. Switch to Layer Comp 2. On the layer called This is, click the visibility icon next to the Layer Style Outer Glow.
A black glow should be added.
7. Click the Create new layer comp icon (it looks like a pad of paper) on the bottom edge of the Layer Comps
window. Name it Comp 2 Alternate.
8. Save a copy of each layer comp to send to a client. Choose File > Scripts > Layer Comps to PDF. Photoshop
creates a new PDF with all four layer comps in one document. This is a convenient way to email a project to a
client for review.
Layer Comps are a bit confusing at ﬁrst, but as you master what layers can do, you’ll turn to Layer Comps for ﬂex-
ibility. Be sure to check out the Adobe Help Center for more on Layer Comps.

Using Blending
Modes
Blending modes are both a mystery and a source
of great design power. Each blending mode
controls how the pixels in one layer are affected
by those in another layer or by a tool from the
9
Tools panel. Most users give up on them because
the technical deﬁ nitions of blending modes get
very tricky. The secret is to not worry too much
about the technical issues and to learn how to
experiment. While you’ll explore the technology
and the creativity behind blending modes, there
are only a few basics that you must know to make
blending modes part of your design toolbox.
About Blending Modes
There are 25 different blending options avail-
able from the Layers panel and a few additional
blending options that work with speciﬁc tools.
How do they work? The simple answer is, it de-
pends. Your response is likely, depends on what?
Simply put, the effect achieved by blending two
layers varies with the contents of those two lay-
ers. A blending mode compares the content of
two layers and enacts changes based on the con-
tent of both layers. You’ll ﬁ nd blending modes
in many of the tools, and they can be combined
with every ﬁ lter.

144 Chapter 9 Using Blending Modes
The blending mode speciﬁed in the Options bar
controls how pixels are affected by a painting or
editing tool. Additionally, you can set the blend-
ing mode of a layer to control how it interacts
with those below it. A clear understanding of the
following terms will better help you understand
blending modes:
• Base color: The original color in the image
• Blend color: The color being applied with
the painting or editing tool (or the color in
the top layer)
• Result color: The color resulting from
the blend
List of Blending Modes
Here are the different blending modes available
through the Layers panel. I have attempted to
give you a clear and simple deﬁ nition as well as a
sample of how these images blend.
NOTE
Blending Mode Practice
For more practice with blending,
open the ﬁles Ch09_Blend Modes1.
psd and Ch09_Blend Modes2.psd in
the Chapter 9 folder, and experiment
with different modes and opacity
settings.
Original Blended Image

About Blending Modes 145
Dissolve Darken Multiply
Creates a random Pixels lighter Is similar to draw-
replacement of than blend are ing strokes on
the pixels with replaced; darker the image with
the base or blend ones are not. magic markers.
color.
Color Burn Linear Burn Darker Color
Evaluates each Evaluates each Uses the lowest
channel; darkens channel; darkens value from both
base by increas- base by decreas- layers to create
ing contrast. ing brightness. resulting color.
Lighten Screen Color Dodge
Evaluates each Results in a Evaluates color
channel; it then lighter color. It is information and
uses base or blend useful for “knock- brightens base
color (whichever ing” black out of by decreasing
is lighter). a layer. contrast.
Linear Dodge Lighter Color Overlay
(Add) Evaluates Uses highest Overlays existing
color information value from both pixels while pre-
and brightens layers to create serving highlights
base by increas- resulting color. and shadows of
ing brightness. base.
Soft Light Hard Light Vivid Light
Effect is similar to Effect is similar to Burns or dodges
shining a diffused shining a harsh by increasing or
spotlight on the spotlight on the decreasing the
image. image. contrast.
Linear Light Pin Light Hard Mix
Burns or dodges Is useful for add- Enhances the
by decreasing or ing special effects contrast of the
increasing the to an image. underlying layers.
brightness.
Difference Exclusion Hue
Evaluates each Is similar to the Uses luminance
channel and sub- Difference mode and saturation of
tracts or inverts but lower in the base and the
depending on contrast. hue of the blend.
brightness.
Saturation Color Luminosity
Creates color Preserves gray Is the inverse
with luminance levels. It’s very effect from the
and hue of base useful for color- Color mode.
and saturation of ing and tinting.
blend.
Open the ﬁle Ch09_Blended_Overlay.psd from the Chapter 9 folder on the CD to experiment with blending modes.

146 Chapter 9 Using Blending Modes
Blending Modes in Practice
So far you’ve looked at blending modes in a strictly technical
sense. While it’s useful to have a clear understanding of the tech-
nology, don’t lose sight of the design possibilities. Blending modes
are a great way to mix layers together. For a designer, this can be
a useful way to create backgrounds for speaker support (like Pow-
erPoint presentations) or DVD menus. Let’s dissect one of those
backgrounds:
1. Open the ﬁ le Ch09_Speaker_Support.psd from the Chapter
9 folder on the CD. This eight-layer document uses blending
modes to create a complex background.
2. Turn off the visibility icons for all but the bottommost two layers.
3. Select the Train layer. It is currently set to the
Overlay blending mode. Changing its blend-
ing mode will create a different look.
4. A useful shortcut to cycle blending modes is
Shift++(plus). This will step you forward in
the blending mode list. Pressing Shift+- (mi-
nus) will step backward through the blending
mode list. If you have a tool selected that
has its own mode settings (such as the Brush
or Gradient tool), the shortcut modiﬁes the
blending mode of just the tool. To quickly
change the mode on a layer, select the Move
tool (V) or Marquee tools (M) ﬁ rst. Ex-
periment with different blending modes and
opacity settings to try out different looks.
5. Repeat your blending mode experimentation
for the Light, Highlights, and Soft Focus layers.
Try out different modes and opacity settings.
6. Select the Blue layer. It is set to the Color
blending mode, which applies its color to all
layers below it. This is a very useful way to
tint multiple layers for a consistent look.

Blending Modes in Action 147
Continue to experiment with different combinations of blending
modes and opacity settings. This sample image provides just a
quick glimpse into the power and ﬂexibility of blending modes.
DESIGN “RULES” FOR BLENDING MODES
VIDEO
Rule #1—Don’t try to memorize how each blending mode works: 29 TRAINING
The good news is that they are grouped by similar traits. As you make Blending Modes
your way through the list, you will notice a gradual progression
through styles. The ﬁrst group darkens your underlying image, whereas
the second lightens it. The third set adds contrast, and the last two
generate dramatic results by comparing or mapping values. Depending
on your sources, some blending modes will generate little or no results.
Sound confusing? Keep reading.
Rule #2—Experiment: The best way to use blending modes is to just
try them out. Clicking through a long drop-down menu is boring. A
much better alternative is to select the Move tool and then use the
Shift++ keyboard shortcut.
Rule #3—Exploit them: Do you need a quick visual pop? Try blending
a blurred image on top of itself. Do you need to tint an image? Place a
solid or gradient on top of the image and change to Hue or Color mode.
Blending modes are available for every ﬁlter (choose Fade Filter from
the Edit menu) and all the Brush tools.
Blending Modes in Action
Now that you have a little practice with blending modes, it’s time
to explore their creative and production side in greater depth.
Blending modes are part of a professional’s workﬂow. The next
three sections showcase a few different ways to better integrate
blending modes for professional results.

148 Chapter 9 Using Blending Modes
Instant Spice
One way to improve a washed out or ﬂat image is through blend-
ing modes. By blending a blurred copy of an image on top of itself,
you can quickly create a visual pop. Let’s give it a try:
1. Open the ﬁ le Ch09_Spice.psd from the Chap-
ter 9 folder.
2. Select the Background layer in the Layers
panel.
3. Duplicate the Background layer by pressing
Command/Ctrl+J.
4. Signiﬁcantly blur the new layer by choosing
Filter > Blur > Gaussian Blur. A value of 25
pixels should do the trick.
5. Select the Move tool by pressing V.
6. Cycle blending modes by pressing Shift++.
Look for modes (such as Overlay or Soft
Light) that increase saturation and add visual
“pop” to the image.
7. If needed, adjust the opacity of the layer as de-
sired. You can quickly change opacity by typ-
ing in the ﬁrst number of an opacity setting,
such as 4 for 40% opacity. You can type 25 to
quickly switch to 25% opacity, for example, if
a more speciﬁc adjustment is required.
Here’s a quick look at how different blending modes can be used to
add instant spice to an image.

150 Chapter 9 Using Blending Modes
Fixing a Shadowed Image
If an image is completely thrown into the shadows, you can turn
to blending modes to shed a little light. In fact, this is a technique
that is often used by law enforcement agencies to enhance security
photos or footage.
1. Open the ﬁ le Ch09_Meter.tif from the Chap-
ter 9 folder.
2. Duplicate the Background layer by pressing
Command/Ctrl+J.
3. Set the top layer to Screen mode. You can
choose it from the pop-up menu in the Lay-
ers panel or press the keyboard shortcut
Shift+Option/Alt+S. The image should ap-
pear signiﬁcantly lighter.
4. You can further lighten the image by placing
another duplicate copy on top. Press Com-
mand/Ctrl+J as many times as needed. Each
will lighten the image further.

Blending Modes in Action 151
Applying a Rubber Stamp
You can also use blending modes to make one image appear as if it
were applied to another. If you add the Free Transform command,
you can make that stamp match the perspective of the photo. Let’s
give it a try:
1. Open the ﬁ les Ch09_Boxes.tif and Ch09_
Logo.psd from the Chapter 9 folder.
2. Select the Logo.psd ﬁ le so it is active.
3. Choose Select > All and then Edit Copy to
add it to your clipboard.
4. Switch back to the Boxes ﬁ le and choose
Edit > Paste.
5. Press Command/Ctrl+T to invoke the Free
Transform command. To harness addi-
tional transformations, right-click/Ctrl-click.
Choose Distort: This will allow you to corner
pin the logo and match its angle to that of the
box.
6. You now need to scale the logo smaller.
Right-click/Ctrl-click and choose Scale.
Shrink the logo so it ﬁts better on the side of
the box.
7. Set the Logo layer to the Multiply blending
mode and lower its opacity to 85%. This will
make the Logo layer appear to be stamped on
the crate.
Table 9.1 provides the keyboard shortcuts to
make it easier for you to use blending modes.

Color Correction
and Enhancement
The primary purpose of Photoshop is to act as a
digital darkroom, where images can be correct-
ed, enhanced, and reﬁ ned. How do you know an
image needs touch-up? You can pretty much as-
10
sume every image can look a little (or even a lot)
better than how the camera captured it. Whether
it’s adjusting the exposure, increasing contrast,
or boosting saturation, Photoshop is the place to
improve an image.
Learning how to spot problems, and then choos-
ing the right correction technique is an essential
part of mastering Photoshop. Several different
tools are available, some more useful than others.
By analyzing the most important tools and deter-
mining in which situations they might help you, a
more thorough understanding of color correction
is possible.
Approach to Color
Correction The image on the top is unretouched. The image on the
bottom has been reﬁned with three adjustment layers:
New users often have a hard time when color one to enhance levels and two to adjust hue and saturation
correcting or enhancing images. They generally of the sky and vegetation. You can open the ﬁle
lose sight of the goal: making the image look Ch10_Desert_Enhance.psd to see the changes.
better and believable. Many users go “too far”
in their quest to ﬁ x images. If the image starts to look fake or too
altered, it will be distracting. While getting it “right” will require
some practice, here’s some general advice to get you started:

154 Chapter 10 Color Correction and Enhancement
• Identify what’s wrong: Before you can ﬁ x a picture, be sure
you have decided on what’s wrong. Is it too dark? Is the sky
washed out? Has the picture faded over time? Make a list and
prioritize the issues you ﬁ nd in each image. It’s easiest to ﬁ x
one problem at a time, and if you identify those problems,
you’ll know when to stop twiddling with the image.
• Work with a copy of the image: Before you start to color
correct an image, you should duplicate it. This way you can re-
turn to an original version if you make a mistake or go too far
in your image touch-up. After opening your ﬁ le, choose File >
Save As and name the duplicate version that will be corrected.
Color correction can be a destructive process, meaning that you
cannot revert to the original state at a later time. By preserving
an original version of the image or employing adjustment lay-
ers, nondestructive editing is possible. Some users also choose to
duplicate the background layer at the bottom of the layer stack.
• Edit with adjustment layers: Adjustment layers allow you to
apply most of the image correction commands as nondestruc-
tive effects. They are added as a layer above the actual image;
the adjustment layer can be blended, masked, or deleted at any
time. Additionally, if you double-click the adjustment
layer’s thumbnail, you can modify its properties in the
Adjustments panel. The same modiﬁcations are avail-
able in both the Adjustments menu and Adjustments panel.
You should work with an adjustment layer whenever possible
because its ﬂexibility will be important for future revisions.
• Get a fresh opinion: It’s not a bad idea to step back and
examine your work. Open the backup copy of the original im-
age and compare it to the image you’ve been working on. This
before-and-after comparison can be very useful. If you have a
fresh set of eyes nearby, ask that person for his or her opinion.
Primary Image Adjustments
Photoshop offers several image adjustments, but only a few are
used most often. Commands such as Levels and Curves are used
by professionals to achieve outstanding results. These professional
imaging techniques may take a little time to get comfortable with,
but the power they offer is worth your investment.

Primary Image Adjustments 155
Levels
The Levels command corrects tonal ranges and color balance
issues. With this command you can ﬁ x poor exposure. Addition-
ally, you can perform color correction by manually identifying a
white point and black point in the image. Nearly every image can
beneﬁt from making a Levels adjustment.
To understand Levels, it is essential to be able to read a histogram.
This graph works as a visual guide for adjusting the image. The
Levels adjustment has its own histogram that is visible when work-
ing in the Adjustments panel. You may also want to call up the
Histogram panel (Window > Histogram) and leave it open while
color correcting. You can also choose to expand the Histogram
panel by clicking the submenu and choosing All Channels View.
Let’s give the command a try.
1. Close any open ﬁ les, and then open the ﬁ le Ch10_Levels.tif
from the Chapter 10 folder on the CD.
2. Add a Levels adjustment layer by clicking the
Levels icon in the Adjustments panel. Levels
is also available from the Adjustments menu
(Image > Adjustments), but the adjustment
layer is more ﬂexible for future modiﬁcations.
Be sure to select the Preview check box so
changes update onscreen.
3. This photo was shot under NOTE
low light, but you can reset
Levels Beats
the black and white points
Brightness/Contrast
of the image to ﬁ x the ex-
posure. In the Adjustments A Brightness/Contrast command
does exist, but the Levels adjust-
panel, move the white Input
ment lets you perform several
Levels slider to the left
improvements with one command.
(where the histogram starts
Using a single image process
to rise). This affects the im- cuts down on the loss of quality
age’s white point and allows introduced from multiple image-
you to reassign where white processing steps.
should begin in the image.

156 Chapter 10 Color Correction and Enhancement
4. Move the black Input Levels
slider to the right where the
ﬁ rst amount of black starts
to rise. The more you move
the black slider to the right,
the more contrast is intro-
duced into the image.
5. The true power lies in the
middle (gray) Input Levels
slider. By moving this slider,
you can modify the gamma
setting. Effectively, you can
use the middle Input Levels
slider to change the inten-
sity of the midtones. This
adjustment can be made
without making dramatic
changes to the highlights
and shadows, and lets you
better expose an image.
Move the slider to the left to
add light; move the slider to
the right to subtract light.
6. In the future if you need to
edit the adjustment, simply
select the adjustment layer
in the Layers panel and
manipulate the controls in
the Adjustments panel.
VIDEO
31 TRAINING
Color Correction—Levels
NOTE
Levels vs Curves
A Levels adjustment does not offer
as many precise adjustment points
as a Curves adjustment. However,
Levels adjustments can be easier to
make and generally produce very
effective results.

Primary Image Adjustments 157
Auto-Levels
When working with the Levels adjustment layer, you may have
noticed the Auto button. This command button triggers an
analysis of the histogram data by Photoshop that is then used to
modify the individual controls of the Levels adjustment. In many
cases this results in an image that is properly adjusted for color
balance and exposure issues. In others it will get you closer to a
corrected image.
1. Close any open ﬁ les, and then Open the ﬁ le Ch10_Auto_Lev-
els.tif from the Chapter 10 folder on the CD.
2. Add a Levels adjustment
layer by clicking the Levels
icon in the Adjustments
panel.
3. Click the Auto button to
perform an automated
adjustment for the image.
The image’s levels and color
are adjusted.
4. To reﬁ ne how the automatic
adjustment works, hold
down the Option/Alt key
and click the Auto button
again. A new dialog box
opens.
5. Choose Find Dark & Light
Colors and Snap Neutral
Midtones to create a very
natural balance of colors for
the image.
6. Click OK to close the dialog
box.